INTEGRATIVE REFLEX DYNAMICS IN RESPIRATORY CYCLE CONTROL

呼吸循环控制中的综合反射动力学

• 批准号: 6109907
• 负责人: EUGENE N BRUCE
• 金额: $ 18.51万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-01 至 2001-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6109907
• 关键词: afferent nerve; brain stem; chemoreceptors; electromyography; laboratory rat; mechanoreceptors; neural information processing; pulmonary respiration; pulmonary stretch receptors; respiratory airway volume; respiratory reflex; vagus nerve

This proposal addresses the hypothesis that respiratory variability is due to an 'instability' in mechanisms for the control of end-expiratory volume (EEV) in animals with compliant chest walls. This 'instability' is a form of complex irregular behavior in the nonlinear dynamics sense. We hypothesize that it is due to interactions of time-varying nonlinear pulmonary mechanoreceptor feedback with integrative central mechanisms for respiratory rhythm and pattern formation. We have described how the sensitivity of respiratory phase transitions to vagal afferent activity causes a variable breathing pattern. This effect is accentuated during lung deflation by continuous negative airway pressure (CNAP) and may be due partly to deflation-sensitive, slowly-adapting pulmonary receptors (DSARS). The present proposal studies intact upper airways to investigate the interactions of the above mechanisms (which control EEV by altering dynamics of respiratory phase transitions) with other mechanisms which control EEV by modulating upper airway expiratory activity. Because both groups of mechanisms are modulated by pulmonary mechanoreceptor feedback, we hypothesize that their interactions will increase the variability of the breathing pattern and may adversely impact gas exchange. additionally we will assess how chemical drive affects these mechanisms. We will also characterize DSARs, comparing them with pulmonary stretch and rapidly-adapting receptors and identifying some of their central projections. The proposed studies will extend current concepts about reflex control of respiratory pattern by examining the breath to breath reproducibility of vagally-mediated reflex effects and elucidating some mechanisms which are expected to impair this reproducibility. Furthermore, analogies with respiratory behavior in human neonates suggest broader applicability of the expected findings.

这一提议提出了这样一个假设，即呼吸变异性 由于控制呼气末的机制的“不稳定性”， 具有顺应性胸壁的动物的EEV。 这种“不稳定” 在非线性动力学意义上，是一种复杂的不规则行为。 我们假设，这是由于时变非线性的相互作用 具有整合中枢机制的肺机械感受器反馈 呼吸节律和模式的形成。 我们已经描述了 呼吸相位转换对迷走神经传入活动的敏感性 会导致不同的呼吸模式 这种影响在 通过持续气道负压（CNAP）进行肺放气， 部分原因是对放气敏感，适应缓慢的肺部受体 （DSARS）。 目前的建议研究完整的上气道， 研究上述机制（控制EEV）的相互作用 通过改变呼吸相变的动力学）与其他 通过调节上气道呼气控制EEV的机制 活动 因为这两组机制都是由肺调节的， 机械感受器反馈，我们假设它们的相互作用将 增加了呼吸模式的可变性 影响气体交换。 此外，我们将评估化学驱动如何 影响这些机制。 我们还将描述DSAR的特征， 他们与肺拉伸和快速适应受体， 找出他们的一些中心投影 拟议的研究将 通过以下方式扩展关于呼吸模式的反射控制的当前概念： 检查迷走神经介导反射的呼吸重复性 影响和阐明一些机制，预计将损害这一点， 再现性 此外，与呼吸行为的类比， 人类新生儿表明预期发现的更广泛适用性。